Does anyone have any experience with mass amount of fish? I know the inch of fish per gallon rule, but this is a holding tank for feeders. I have about 6 lbs of goldfish in a 50gal tote, two airstones, canister fliter and a regular overhead filter. It was serving the purpose when I was housing about 3lbs of minnows, but now that I made the jump to gold fish, there dying off about 70-100 a day. If I am to save these fish I need to do 100% water change, but all i have is city water and prime (not good for 100%). I really need to start dreaming up a tank solution without sacrificing my swimming pool =) I eventually will get maybe a barrel, maybe 2 (that should give me ~ 160 gals if I pipe them together. Long story short i need some advice on

A. What I can do right now to salvage the fish I have left
B. Cheap tank/filtration ideas that would be better

P.s. 1 lb = ~ 300fish

I know Im going to get some grief about it being to small, but I want you to picture that 55 gallon fishtank with a sump, and a airstone at your local lakes holding about 5,000 minnows. I am ok with losing about 20 fish a day, but 70-100 is kicking my rear even thou Its still better than buying 30 fish a day @ .12cents a fish @ my local petstores.

You do know goldies are probably the worst thing you can use for feeder, you would be much better off using guppies or minnows. Goldfish contain a lot of toxins and have very little nutritional value.

But on to your question. What are your stats? Ammonia, Nitrite, nitrate. My guess is that the increase in fish, especially goldfish. Which produce a lot of waste, has caused a mini-cycle. I would do a very large water change using the prime, there should be no issues with that. Also if you do have ammonia or nitrite double dose the prime, if you don't have test kits double dose as well.

If you are looking for a larger container go to fleetfarm and in the back they sell troughs for livestock. They are large plastic round or oval containers anywhere from 50-300gal. You may need more filtration if you increase the size of the container. Being a feeder tank ideally you want a lot of filtration, it may be a good idea to get a small pond filter or modify a pool filter.

I find it disturbing more than 30 would die each day. Try to read this and see for yourself why goldfish is not a suitable feeder fish, contrary to popular beliefs. Mikaila is quite correct in putting her foot down about these goldfish being used as feeders. Very poor nutritional value and plenty of thiaminase to counter the Vitamin B1 which in turn causes the fish to become malnourished.Article: Thiaminase – What it is, why you care

Thiaminase destroys Thiamine (Vitamin B1). Goldfish & Rosie Reds (and most cyprinidae) contain a very high level of thiaminase. Thiamine deficiency can lead to a myriad of problems including neurodegeneration, wasting and death. Tissue Distribution in many living animals is dependent on Thiamine levels. Once Thiaminase is ingested, it has very long lasting effects and does not purge itself from the body. Lack of Thiamine (Vitamin B1) is the primary reason why fish would not be able to properly produce fleshy tissue.

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When our LFS was using a 150g livestock tub for feeders (goldfish) we were using a jumbo (about 20 gallon volume) wet dry tower, plus a constant daily water change (maybe 10-20g per day, maybe more - it was a constant flow system ) and were still just able to do about 300 goldfish before losses moved to the unprofitable range.

You need cold water, high oxygen content, a huge wet-dry filter (canister won't cut it) and lots and lots of water changes.

As was stated - goldfish will eventually kill whatever you are feeding them to. The cost of goldfish isn't the cost per feeder, its the cost per parasite or infection - plus the thiaminase issue.

Not sure where you are but most Home Depots, Lowes and I've even seen the big black tubs at Walmart. They're normally over by the pond supplies outside and not very expensive. The matter at hand is you have the fish so we have to deal with that before they all die on you. I would get a bigger "tank". Those big tubs are used for ponds so I thing those should work just fine. another option would be a very large tupperware container. I would probably do more than 1 due to the amount of fish but you get the point.

Make sure it has several airstones. This will keep the water moving and oxygen in the water. GF are hardy but you still don't want your levels to be off the wall so I'd test just to see where you stand. Make sure the water your putting back in the tank after water changes is treated to get rid of chlorine. I swear by my Cycle. It helps with so many issues.

How long have you had these fish? How did you get them? Is this something that was shipped to you? Maybe you're loosing them from shipping stress.

If you want them to reproduce quickly, get 3 males and 6 to 8 females. Just make sure to place some fake or real plants to provide cover for the fry since they could get eaten by the parents. Other decorations are fine too, practically anything that the babies can hide in.